Redokstsüklid

Redokstsüklid, also known as redox cycles or oxidation-reduction cycles, are fundamental biochemical processes that involve the transfer of electrons between molecules. These cycles are crucial for energy production in living organisms, as well as for various metabolic pathways. At their core, redox cycles involve a sequence of oxidation and reduction reactions. Oxidation is the loss of electrons, while reduction is the gain of electrons.

A classic example of a redox cycle is the Krebs cycle, also known as the citric acid cycle or TCA cycle. This cycle is a central part of cellular respiration, where acetyl-CoA is oxidized to produce ATP, NADH, and FADH2. These electron carriers then play a vital role in the electron transport chain, the primary site of ATP synthesis. Other important redox cycles include those involved in photosynthesis, where light energy is used to drive the reduction of carbon dioxide into sugars.

Redox cycles are also implicated in various physiological and pathological processes. For instance, reactive oxygen species (ROS) are byproducts of some redox cycles and, while they can have signaling roles, excessive ROS can lead to oxidative stress and cellular damage, contributing to aging and diseases like cancer and neurodegenerative disorders. Understanding redox cycles is therefore essential for comprehending cellular metabolism, energy homeostasis, and the mechanisms underlying health and disease.